"They bite because they're hungry, and testicles sit nicely in their mouth," he explained.

"And its mouth is not so big, so of course it normally eats nuts, fruit, and small fish, but human testicles are just a natural target. It's not normal to get your testicles bitten off, of course, but it can happen, especially now in Sweden."

While Carl said the museum's warning about the pacu, sometimes known as the "ball cutter", was meant "as a bit of fun", human victims of the pacu are rarely laughing.

This a typical tabloid nonsense story. Despite the story being about pacus they show photos not of pacu's teeth, which presumably is what people might be actually interested in, but a photo of piranha's teeth - because it's a close relative. Well the neon tetra is also a relative yet no photos of pretty neon tetras, I wonder why ?

There hasn't ever been a single reported testicle eating incident in the pacu's Amazon Basin home, and the entire "ball cutter" nickname appears to originate from the claims of one fisherman in Papua New Guinea, who apparently managed to make a positive identification despite just having his balls ripped off.

I don't know what temperature and salinity the water in Sweden's Oresund Sound has but I would be amazed if a fish which has evolved to live in the Amazon Basin survived for more than a few hours there.

Despite the story being about pacus they show photos not of pacu's teeth, which presumably is what people might be actually interested in, but a photo of piranha's teeth - because it's a close relative.

Maybe the fish had work done? Almost certainly those sharks have veneers ...

I'm talking about the photo in the OP's linked article, which despite the article being specifically about pacus, they show a photo of piranha's teeth. I wasn't referring the photo posted on the thread.